I have a white 4x4 with a logo and black stickers for my white side since my cube has white plastic. Can I use my black stickers or should I get white ones? I took the sticker with the logo and flipped it over and glued it on. Now I can't see the logo. I also put the thin layer of stuff originally on it back on. It has really small air bubbles on it. I can't feel them though. And I'm not good enough at cubing (I ave around 27.5 - 32.5 seconds on 3x3 and 3 mins on 4x4). Is my cube OK to use in competitions? I'm not even half way through all the regulations yet.